Spindle drive assembly for a surface-treating machine

ABSTRACT

A spindle drive assembly for a surface-treating machine driven by a portable electric motor mounted in a housing and having a drive pinion engaging said assembly. The spindle is journaled in the housing perpendicular to the drive pinion. A driven gear is affixed to and axially slidable along, the spindle in superposition to and in operative engagement with, the drive pinion. Face apertures are formed on the upper face of the driven gear and a pin carried by the housing is mounted normally out of engagement with the face apertures, but manually depressible into one of the face apertures to lock the driven gear and spindle against rotation. In the preferred embodiment the lock pin will be mounted in a removable cover, so as also to provide access for mounting the spindle. A resilient means such as a bellville washer, is disposed between the housing at the journal and the driven gear, so that on assembly tightening of the nut to affix the spindle and lock the driven gear in position may be suitably tightened to provide for a predetermined engagement between the drive pinion and the driven gear, whereby the pitch diameters of the respective pinion and gear substantially will lie at a predetermined location to permit transmission of maximum torque with minimum wear and backlash.

United States Patent 11 1 Batson 1 SPINDLE DRIVE ASSEMBLY FOR A SURFACE-TREATING MACHINE [75] Inventor: William A. Batson, Pickens, SC.

[73] Assignee: The Singer Company, New York,

[22] Filed: Aug. 23, 1974 [21] Appl. No.: 499,814

[52] US. Cl 51/170 T; 74/411.5; 74/527 [51] Int. CL B24B 23/00; G05G 5/06 [58] Field of Search 51/170 T, 170 PT, 170 R; 74/411.5, 527; 173/163 [56] References Cited UNITED STATES PATENTS 1,270,808 7/1918 Franklin 51/170 T 1,503,723 8/1924 Strorn 51/170 PT 1,653,108 12/1927 Koenig 51/170 T 1,770,549 7/1930 Peterson... 51/170 T 2,101,305 12/1937 A1bertson.. 51/170 T 2,211,216 8/1940 Oster 51/170 P T 2,267,781 12/1941 Albertson 51/170 T 2,687,046 8/1954 Vorech 74/527 3,021,723 2/1962 l-lappe 74 41 1.5 3,334,448 8/1967 AleXander.... 51/170 T 3,371,735 3/1968 Masera 74/41 1.5

L. Bell; Harold Weinstein Aug. 19, 1975 5 7 1 ABSTRACT A spindle drive assembly for a surface-treating machine driven by a portable electric motor mounted in a housing and having a drive pinion engaging said assembly. The spindle is journaled in the housing perpendicular to the drive pinion. A driven gear is affixed to and axially slidable along, the spindle in superposition to and in operative engagement with, the drive pinion. Face apertures are formed on the upper face of the driven gear and a pin carried by the housing is mounted normally out of engagement with the face apertures, but manually depressible into one of the face apertures to lock the driven gear and spindle against rotation.

substantially will lie at a predetermined location to permit transmission of maximum torque with minimum wear and backlash.

7 Claims, 6 Drawing Figures 20 110 52 SPINIDLE DRIVE ASSEMBLY FOR A SURFACE-TREATING MACHINE BACKGROUND OF THE INVENTION Heretofore, the spindle drive assembly for a surfacetreating machine having a right angle drive, were usually connected with the drive spindle atop the driven gear. This hampered and limited the mounting tolerances and the adjustment for backlash. Additionally, it created a crowded condition in the gear housing wherein the spindle lock would have to be placed externally of the housing, thus, adding to the complexity of the structure and cost of the tool.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved spindle drive assembly for a surface-treating machine which overcomes the prior art disadvantages; which is simple, economical and reliable; which is used in conjunction with a segmented housing; which is used in connection with a segmented housing having a gear chamber with a removable cover; which includes a spindle lock therein; which includes a pin for locking the spindle which is carried in the re movable cover; which has a driven gear carried by the spindle in superposition to the drive pinion; which has a superpositioned driven gear carried by the spindle having face apertures in the upper sides thereof, for engagement by a lock pin mounted in the housing; and which permits the adjustment of the pitch diameter of the driven gear to substantially eliminate any backlash in the drive assembly.

Other objects and advantages will be apparent from the following description of one embodiment of the invention, and the novel features will be particularly pointed out hereinafter in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS This invention is illustrated in the accompanying drawings in which:

FIG. 1 is a side elevational view of a surface-treating machine embodying the present invention.

FIG. 2 is a perspective view of the surface-treating machine of FIG. 1, and embodying the present invention.

FIG. 3 is an enlarged elevational view, partly in section, of the front segment of the housing of the machine, and embodying the present invention.

FIG. 4 is an exploded elevational view, partly in section, of the housing segment shown in FIG. 3.

FIG. 5 is a partial view of the improved pin arrangement, diagrammatically representing the locking operation of the driven gear.

FIG. 6 is a fragmented and exploded view of the improved pin subassembly, and portion of the housing for mounting the same.

DESCRIPTION OF THE INVENTION In the illustrated embodiment of the invention, there is shown in FIGS. 1 and 2, an electrically driven portable surface-treating machine, designated generally 10, which is suitable for use in sanding, polishing, or general abrading operations, and includes the improved right angle spindle drive assembly 12, shown best in FIG. 3.

The machine 10, illustrated in FIGS. 1 and 2, is provided with a segmented housing 14, which includes a rear segment 16, a middle segment 18 and a front segment 20. The various housing segments are connected together by screw means 22 interconnecting adjacent segments 16, I8 and 18, 20 of the housing 14. A universal motor 24 is mounted in the middle segment 18 and connected in circuit through an on-off trigger switch 26 and a two-position speed switch 28, and to a suitable source of electric potential by means of a line cord 30. The motor 24 has an armature 32 carried on an armature shaft 34 joumaled in the housing 14, as illustrated in FIGS. 1 and 3.

The main handle 36 is formed integrally with the rear segment 16. The main handle 36 is positioned to be convenient for operation of the switches 26 and 28, also carried in the rear segment 16. A second handle 38 is detachably connected to one side of the front segment 20 for added convenience of operation and manipulation of the machine 10.

A spindle 40 is included in the drive spindle assembly 12, and is disposed at right angles to the armature shaft 34 to have its lower end extend downwardly and outwardly of the front segment 20 of the housing 14 for connection thereto by a pad assembly 42 for accomplishing the desired sanding, polishing or other work operation of the machine 10.

Ventilation for the motor 24 of the machine I0 is provided by entry of cooling air into slots 44 formed in the sides of the rear segment 16 of the housing 14, with exit of the air at slots 46 formed at the mating line of the front and middle segments 20 and 18, adjacent the fan 48, carried by the armature shaft 34 shown in FIG. 1, which fan rotates during operation of the motor 24 to insure an adequate flow of cooling through the housing 14. Secondary exit slots 50 illustrated in FIG. 3 are formed in the lower right hand portion of the front segment 20 of the housing 14 to insure proper circulation of the cooling air. The top surface of the housing 14 has a pair of spaced bumpers 52 and 54, with bumper 52 dipsosed transverse of and connected to the front segment 20, and the bumper 54 centered on the rear segment 16. The bumpers 52 and 54 permit the machine 10 to be laid on its top surface during periods of nonoperation thereof.

The armature shaft 34 is split as at 56 at a front journal 58 thereof, to define a front stub shaft 60 which is non-rotatably connected to the rear portion of the armature shaft 34 and extends outwardly through the journal 58 to terminate in a drive pinion 62 formed on the left end of the stub shaft 60, as viewed in FIG. 3. The armature shaft 34 and the stub shaft 60 are disposed along the same axial line. The drive pinion 62 extends into the front segment 20 and lies in spaced relationship to a sleeve 64 which carries vertically spaced bearings 66 and 68 which journal the spindle 40 within the lower wall.

The spindle 40 has a threaded end 70 to which the pad assembly 42 is connected. Upwardly of the section 70, the spindle 40 has a section 72 formed of slightly larger diameter which serves to abut the bearing 68 in which a section 74 thereof is seated. A section 76 of slightly smaller diameter is formed above section 74 and serves to abut against bearing 66, upon which a section 78 is seated. The section 78 has a circular keyway 80 formed therein adjacent its upper end. The spindle 40 is necked down at its upper end at a threaded end 82 which has a transverse aperture 84 formed a short distance from the topmost edge of the end section 82. Resting upon the bearing 66 is a bellville spring washer 86 with the curvature thereof facing upwardly to engage the underside of a downwardly facing gear 88 having annular teeth 90 mating with and driven by the drive pinion 62. The gear 88 has a hub 92 with a vertical slot 94 which extends a short radial distance outwardly from the central aperture 96 which seats the hub 92 upon the section 78 of the spindle 40. A key 98 is seated within the keyway 80 to be axially slidable within the slot 94 to permit adjusting of the relative position of the driven gear 88. The upper side of the gear 88 has a plurality of face apertures 100 formed therein for purposes more fully explained hereinafter.

A washer 102 sits atop the upper end of the hub 92. A castellated nut 104 is threadedly received on the end 82 and tightened a predetermined amount so as to set the pitch diameter of the gear 88 with respect to the drive pinion 62 for maximum torque and minimum wear and backlash, thus, making for an ideal engagement at pitch diameter thereof. To maintain the desired position of the nut 104, a lock or carter pin 106 is connected into the aperture 84 to engage the castellated nut 104 and lock the same in position. Accordingly, the right angle spindle drive assembly 12 includes the mounting sleeve 64, the journal bearing 66 and 68, the spindle 40, the key-connected gear 88 and the nut 104 and lock pin 106.

The front segment defines a gear chamber 108, the upper half of which is enclosed by a detachable cover member 110 secured to the front segment 20 by means of screws 112 shown in FIG. 4, being threadedly received in tapped holes 114 formed in the cover 110.

The cover member 110 has a downwardly extending boss 116, as shown in FIGS. 3 and 6, which receives a pin 118 having an enlarged button head 120, slidably disposed within the boss 116. A spring 122 is trapped between the underside of the button 120 and the bottom wall of the boss 116. A snap ring 124 is mounted into an annular groove 126 upon the pin 118 being depressed into and through the bottom opening of the boss 116 to entrap the spring 122 in position, thus locking the pin 118 in the upwardly biased position shown in FIGS. 2, 3 and 4.

Whenever it is desired to change the pad assembly 42,'the operator as illustrated in FIG. 5, will depress the button 120 to lock the lower end 128 into one of the face apertures 100. The snap ring 124 will act as a stop means by resting upon the upper surface of the gear 88 prior to the spring 122 being completely depressed. Since the pin 118 is in superposition to the center line of the circle upon which the face apertures 100 are formed, it is a simple matter of merely hand turning the pad until the pin 118 drops into one of the face apertures 100 while finger pressure is maintained upon the button 120.

Assembly of the spindle 40 is greatly simplified by providing a removable cover member 110. Assuming the cover 110 has not yet been mounted, the spindle 40 will be inserted upwardly into the sleeve 64 to be journaled into the bearings 66 and 68, so that with the bellville spring washer 86 and the key 98 in place, the driven gear 88 will be placed upon the section 78 to have the key 98 disposed within the slot 94. The washer 102 is then placed prior to the nut 104 being tightened in position. If desired, the spindle 40 may be prepressured upon tightening of the nut 104. In any event, the pressure will be adjusted so that the driven gear 88 and the drive pinions 62 will come into ideal engagement at pitch diameter. Thereafter, the right angle spindle drive assembly 12 will be completed by insertion of the lock pin 106. Attaching the cover member to the front segment 20 will serve to enclose the gear chamber 108.

It will be understood that various changes in the details, materials, arrangements of parts and operating conditions which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principles and scope of the invention.

Having thus set forth the nature of the invention, what is claimed herein is:

1. A spindle drive assembly for a surface-treating machine driven by a portable electric motor mounted in a housing and having a drive pinion engaging said assembly, said assembly comprising:

a. a spindle joumaled in the housing perpendicular to the drive pinion,

b. a driven gear affixed to the spindle in superposition to and in operative engagement with the drive pinion,

c. face apertures formed on the side of the driven gear opposite the drive pinion, I

d. a pin carried by the housing for engaging any one of the face apertures,

e. means connected to the pin to normally bias the pin in the direction away from the face apertures, and

f. manually operated means formed on the pin for operator actuation in overcoming the bias means to urge the pin to engage one of the face apertures to lock the driven gear and the spindle against rotation.

2. The combination claimed in claim 1 wherein:

a. a gear chamber formed in the housing,

b. the spindle mounted in the gear chamber,

0. the gear chamber having an open top, and

d. a cover means detachably connected to the housing to cover the open top of the gear chamber.

3. The combination claimed in claim 2 wherein:

a. the pin operatively connected to the cover means,

b. spring means normally bias the pin out of engagement with the face apertures, and

c. the pin disposed in superposition to the face apertures and is depressible into engagement with one of the face apertures to lock the driven gear and the spindle.

4. The combination claimed in claim 3 wherein:

a. the face apertures are formed with an axis parallel to the axis of the spindle, and

b. the pin is depressibly mounted in the cover means with its axis parallel to the axis of the spindle.

5. A spindle drive assembly for a surface-treating machine having a work engaging member driven by a portable electric motor mounted in a housing and having a drive pinion driving the assembly, said assembly comprising:

a. a gear chamber formed in the housing,

b. the gear chamber having an open portion,

c. a cover detachably connected to the housing to enclose the open portion of the gear chamber,

d. a spindle joumaled in the gear chamber perpendicular to the drive pinion,

e. a driven gear non-rotatively connected to and axially shiftable on the spindle.

f. a resilient means interposed between the journal and the driven gear, g. the driven gear disposed in superposition to and operative engagement with the drive pinion, and h. connecting means affixed to the spindle to urge the driven gear in the direction of the resilient means to set the pitch diameter thereof for engagement with the drive pinion for transmission of maximum torque and minimum wear and backlash in said drive assembiy.

6. The combination claimed in claim 5 wherein:

a. the driven gear having at least one aperture formed on its outer periphery,

b. a pin mounted in the cover.

c. spring means normally biasing the pin in the direction away from the driven gear, and

d. the pin being depressible into engagement with the aperture to lock the driven gear and the spindle from rotation.

7. The combination claimed in claim 6 wherein:

a. the aperture formed on the upper face of the driven gear,

b. a boss formed in the cover,

c. the pin mounted in the boss,

d. the spring means entrapped between the boss and the pin,

e. the lower end of the pin extending below the boss in the direction of the driven gear,

f. an annular groove formed on the lower end of the pin, and

g. a snap ring connected into the annular groove to prevent removal of the pin from the boss and to limit the insertion of the lower end of the pin into the face aperture by seating upon the upper face of the driven gear. 

1. A spindle drive assembly for a surface-treating machine driven by a portable electric motor mounted in a housing and having a drive pinion engaging said assembly, said assembly comprising: a. a spindle journaled in the housing perpendicular to the drive pinion, b. a driven gear affixed to the spindle in superposition to and in operative engagement with the drive pinion, c. face apertures formed on the side of the driven gear opposite the drive pinion, d. a pin carried by the housing for engaging any one of the face apertures, e. means connected to the pin to normally bias the pin in the direction away from the face apertures, and f. manually operated means formed on the pin for operator actuation in overcoming the bias means to urge the pin to engage one of the face apertures to lock the driven gear and the spindle against rotation.
 2. The combination claimed in claim 1 wherein: a. a gear chamber formed in the housing, b. the spindle mounted in the gear chamber, c. the gear chamber having an open top, and d. a cover means detachably connected to the housing to cover the open top of the gear chamber.
 3. The combination claimed in claim 2 wherein: a. the pin operatively connected to the cover means, b. spring means normally bias the pin out of engagement with the face apertures, and c. the pin disposed in superposition to the face apertures and is depressible into engagement with one of the face apertures to lock the driven gear and the spindle.
 4. The combination claimed in claim 3 wherein: a. the face apertures are formed with an axis parallel to the axis of the spindle, and b. the pin is depressibly mounted in the cover means with its axis parallel to the axis of the spindle.
 5. A spindle drive assembly for a surface-treating machine having a work engaging member driven by a portable electric motor mounted in a housing and having a drive pinion driving the assembly, said assembly comprising: a. a gear chamber formed in the housing, b. the gear chamber having an open portion, c. a cover detachably connected to the housing to enclose the open portion of the gear chamber, d. a spindle journaled in the gear chamber perpendicular to the drive pinion, e. a driven gear non-rotatively connected to and axially shiftable on the spindle, f. a resilient means interposed between the journal and the driven gear, g. the driven gear disposed in superposition to and operative engagement with the drive pinion, and h. connecting means affixed to the spindle to urge the driven gear in the direction of the resilient means to set the pitch diameter thereof for engagement with the drive pinion for transmission of maximum torque and minimum wear and backlash in said drive assembly.
 6. The combination claimed in claim 5 wherein: a. the driven gear having at least one aperture formed on its outer periphery, b. a pin mounted in the cover, c. spring means normally biasing the pin in the direction away from the driven gear, and d. the pin being depressible into engagement with the aperture to lock the driven gear and the spindle from rotation.
 7. The combination claimed in claim 6 wherein: a. the apertuRe formed on the upper face of the driven gear, b. a boss formed in the cover, c. the pin mounted in the boss, d. the spring means entrapped between the boss and the pin, e. the lower end of the pin extending below the boss in the direction of the driven gear, f. an annular groove formed on the lower end of the pin, and g. a snap ring connected into the annular groove to prevent removal of the pin from the boss and to limit the insertion of the lower end of the pin into the face aperture by seating upon the upper face of the driven gear. 